Results of this Phase I research have amply demonstrated the effectiveness and practically of laser trephination of the cornea. It is proposed to continue this project through the development and testing of a complete laser corneal surgical instrument. The final instrument will include a 2nd generation pulsed HF laser; an optical delivery and alignment system; an operating table, operating microscope, and hardware to position and stabilize the target cornea; a microcomputer interfaced to laser and optical delivery system to provide control and monitoring of the instrument and the surgical procedure. The surgeon will operate the instrument via the microcomputer keyboard, and/or via hand or foot controls interfaced to the microcomputer. The overall goal of the Phase II project is to complete instrument development, to verify instrument performance by corneal surgical studies, and finally to use the instrument for donor tissue trephination in human cornea transplantations. An IDE for both donor and recipient tissue use of the instrument in human transplantations will be applied for during the Phase II period.